Yes to each their own. I dont feel like arguing something that only takes a little common sense. Two years is not a long time for a frog to live....ask experts on this site and veterinarians for their opinions and 99 percent will agree not to mix.
We take these animals out of the wild to keep them for our personal pleasure. Why take it a step further and mix several species. These animals would not live ontop of each other naturally in the wild so would we throw them in a tiny glass box and force them to live in this manner. Just because we CAN do these things does not mean that it is whats best for them.
I want people who are inexperienced and are reading this thread to understand both angles. Your opinion that it is okay, and mine that it is certainly not. Let them come to their own conclusions with the information provided.
I am curious if you are talking about this book: Care and Breeding of Popular Treefrogs by Philippe De Vosjoli. If so what year was it written.